1. Field of the Invention
The present invention generally relates to an apparatus and method for routing telephone calls in a telecommunications network according to the geographic location from which the call originates. More particularly, the present invention relates to an application in an Advanced Intelligent Network (AIN) for routing calls to a closest of a plurality of branch or satellite offices based upon the geographic area in which the call originates, e.g., according to the zip code+4 of the caller.
2. Acronyms
The written description provided herein contains acronyms which refer to various communication services and system components. Although known, use of several of these acronyms is not strictly standardized in the art. For purposes of the written description herein, acronyms will be defined as follows:
AIN—Advanced Intelligent Network
CCS—Common Channel Signaling
CENTREX—Central Exchange Service
CIC—Carrier Identification Code
CO—Central Office
CPR—Call Processing Record
DID—Direct Inward Dialing
DRS—Data Reporting System
ILEC—Independent Local Exchange Carrier
ISCP—Integrated Service Control Point
IXC—Interexchange Carrier
LATA—Local Access and Transport Area
LIDB—Line Information Data Base
LVAS—Line Validation Administration System
NPA—Number Plan Area
NXX—Central Office Code
PBX—Private Branch Exchange
PIC—Presubscribed Interexchange Carrier
SCP—Service Control Point
SS7—Signaling System 7
SSP—Service Switching Point
STP—Signaling Transfer Point
TCAP—Transaction Capabilities Applications Part
TCP/IP—Transmission Control Protocol/Internet Protocol
WAN—Wide Area Network
3. Background and Material Information
In recent years, a number of new telephone service features have been provided by an Advanced Intelligent Network (AIN). The AIN evolved out of a need to increase the capabilities of the telephone network architecture to meet the growing needs of telephone customers. The AIN architecture generally comprises two networks, a data messaging network and a trunked communications network. The trunked communications network handles voice and data communications between dispersed network locations, whereas the data messaging network is provided for controlling operations of the trunked communications network.
An illustration of the basic components of an AIN architecture is shown in FIG. 15. As shown in FIG. 15, Central Offices (CO) 64–70 are provided for sending and receiving data messages from a Service Control Point (SCP) 56 via a Signaling Transfer Point (STP) 58–62. The data messages are communicated to and from the COs 64–70 and the SCP 56 along a Common Channel Signaling (CCS) network 88. Each CO 64–70 serves as a network Service Switching Point (SSP) to route telephone calls between a calling station (e.g., station 72) and a called station (e.g., station 84) through the trunked communications network 90–92. For More information regarding AIN, see Berman, Roger K., and Brewster, John H., “Perspectives on the AIN Architecture,” IEEE Communications Magazine, February 1992, pp. 27–32, the disclosure of which is expressly incorporated herein by reference in its entirety
A number of features provided by prior AIN or AIN-type intelligent networks relate to specialized call processing of incoming calls.
For example, U.S. Pat. Nos. 4,611,094 and 4,611,096, both to ASMUTH et al., disclose a system for providing custom incoming telephone call processing services to a subscriber operating at many geographically diverse locations. A subscriber program stored in a central database is accessed to provide instructions to the SSPs to complete incoming calls to one of the subscriber locations in accordance with special services defined by the subscriber. The subscriber program controls the Action Control Points (ACP) to string together the desired call processing capabilities to process each call. Specified parameters stored in the program, such as time of day, caller location and data inputted by the caller, determine the final destination to which each call should be completed.
U.S. Pat. No. 4,788,718, to McNABB, teaches centralized recording of call traffic information. The system provides a data gathering and recording function to the centralized database which stores the subscriber's call routing program. The subscriber's call routing program performs several functions, including presenting various announcements to callers, prompting callers for inputting information digits and collecting the resulting information digits, routing the call to a number provided by the subscriber, and performing final call dispositions other than routing to the telephone number provided by the subscriber. Processing of the call traffic information dynamically canards the subscriber's call routing program to reduce the number of blocked calls to the subscriber's telephone numbers.
U.S. Pat. No. 5,247,571, to KAY et al., discloses an Area Wide Centrex system to provide specialized calling features to stations connected to a plurality of central offices. Each of the central office switching points connects to a number of local telephone lines. The features are extended to the local telephone lines by taking the programming intelligence out of the central offices and moving it to a database located at a centralized location, such as an SCP. Service features are controlled by the central database and are changed by reprogramming the service logic located at the central database. A variety of service features are provided including a work at home service that enables a user of a private network access from a home telephone and access authorization to increase the security of the private network.
U.S. Pat. No. 5,353,331, to EMERY et al., discloses an AIN system which connects to, and controls processing of, calls to a subscriber's wireless handset via a home base station or wireless communication network. In response to calls directed to the subscriber's wireless handset, the AIN determines where the handset is located using a central database and routes the call to that location. The incoming call can be routed directly to the handset, blocked, or routed to an alternate termination point. In response to calls from the handset, the central database provides instruction data to the land line network to extend a requested special service to the subscriber.
While prior AIN or AIN-type intelligent network applications have provided various call forwarding features to subscribers and users, such prior attempts have not automatically ascertained the geographic location of the call origination so as to route the call to a nearest termination telephone number as more fully described herein. Further, such prior attempts nave not provided flexibility to subscribers in terms of providing various routing options that may be combined with routing based on geographic location of the call.
These features would be highly desirable to users or subscribers, i.e., businesses with many satellite offices within a single geographic area so that customers, by calling a single publicized telephone number, will automatically be routed to the closest office location of the subscriber. The ability to combine geographic routing with other routing options (time-of-day, day-of-week, specific date, percent allocation distribution, etc.) would also be beneficial to businesses by providing proper and automatic routing of calls from customers. Further, by using a single publicized telephone number, up-front investment costs of the subscriber's premises equipment and advertising costs are reduced, customer's efforts to contact a convenient location of the subscriber are aided, and fast reliable service to subscribers and their customers is provided.